Pet toothbrush



FIG. 1 is a front view of a pet toothbrush comprising the present invention;

FIG. 2 is a top view thereof;

FIG. 3 is a side view thereof, the opposite side being a mirror image;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a rear view thereof. 

The ornamental design for a pet toothbrush, as shown and described. 